Reminds me of a story about the great comedian and wit, Fred Allen. Once he went on vacation to finish writing a book. So as not to be disturbed he put out a sign on his front porch that said No Salesmen or Peddlers Allowed. Then one day his bell rang and he answered the door only to be met by a man selling encyclopedias. Annoyed Allen pointed to the sign, and the man then confessed that he could not read.
After dismissing the salesman, Allen called to his wife Portland saying that he really blamed himself for the interruption. He declared, How dare I fail to anticipate the illiterate.